Adjustable scaffold



Aug. 13, 1968 Q E. o. PERRY ADJUSTABLE SCAFFOLD 2 Sheets-Sheet 1 Filed Nov. 25. 1966 I I /l0 50654;: n. PERRY ATTORNEY Aug. 13, 1968 E. DIP RRY 3396,81?

ADJUSTABLE SCAFFOLD Filed Nov. 25, 1966 2 Sheets-Sheet 2 INYENTOR; EUGENE D. PERRY BY W ATTORNEY United States Patent Office 3,396,817 Patented Aug. 13, 1968 ADJUSTABLE SCAFFOLD Eugene D. Perry, Mooresville, Ind., assignor to Perry Manufacturing, Inc., Indianapolis, Ind. Continuation-impart of application Ser. No. 330,700, Dec. 3, 1963. This application Nov. 25, 1966, Ser. No. 597,020

11 Claims. (Cl. 182-187) The present invention is a continuation-in-part of applicants co-pending US. patent application, Ser. No. 330,700, filed Dec. 16, 1963 and now abandoned, entitled Adjustable Scaffolding.

This invention relates to scaffolding, and more particularly scaffolding which is adjustable to provide desired variation of operative or working height.

The general object of the invention is to provide scaffolding which is of sturdy construction, and which has novel and advantageous means to rigidly support the working platform thereof in any selected position of height adjustment, but which is of economical construction and is convenient in use and in height-adjustment. This present invention provides the additional concept of even a more positively-operative holding means for the extra safety of assuring that the holding means will be positively retained in the height-adjustment desired; and further height adjustment-convenience is provided by the fact that the same components, which are manually moved to effect disengagement of one of the holding means, are the same components which are manually moved to effect disengagement of the other holding means, yet the manual motions are different, thus rendering any accidental or inadvertent disengagement of both holding means effectively impossible. Thus extra high safety for the scaffold height-adjustment is achieved with but little added inconvenience.

Accordingly, there is provided a vertical end-frame for each end of the scaffold for supporting the .working platform, and there is provided at each end of the platform a pair of supports which slidably engage vertical portions of the end-frames. Releasable, spring-pressed latch means having axially movable .pins interengage between the supports and the end-frames, for fixing the height of the pl-at form with respect to the end-frames and thus to fix the operative height of the platform. Height-adjustment is very convenient and rapid, with no tools, yet the platform is securely held in the desired position, with no chance of slipping.

The extra holding means is achieved by providing a screw-thread means fixed to each of the said pins; and the support-mounted components which slidably receive the said pins are provided with co-operative screw-thread means which provide that the pins may be screw-threadedly held in their latched or elevation-maintaining posi tion, providing extra safety for the scaffold; and double function is achieved by the pin-spring thus automatically serving to maintain the frictional engagement of the screwthreads, and by the pin-carried screw-thread component being the manually-manipulatable member for the operator effecting the disengagement both of the screw-thread retaining means and of the axially movable pin.

The description so far given is introductory and of a general nature; and these and more specific concepts, objects, and advantages will be more apparent from the following, more detailed description of an illustrative embodiment of the invention, reference being had to the accompanying somewhat diagrammatic drawings, in which:

FIG. 1 is aside elevational view of an adjustable scaffold according to one embodiment of the present invention;

FIG. 2 is a cross-sectional view thereof, taken generally along section-line II-II of FIG. 1;

FIG. 3 is a cross-sectional view in enlarged scale through one of the end-frame legs, being taken generally along section-line III-III of FIG. 2, the holding pin being shown in a partially-retracted position, and with two sets of fragmental chain lines indicating progressively latching-insertion positions of the holding pin; and

FIG. 4 is a horizontal cross-sectional view through a leg of one of the end-frames, being taken generally along the section-line IV-IV of FIG. 2.

As shown in the drawings, the adjustable scaffolding accord-ing to an embodiment of the present invention generally includes a horizontal working platform 10, and vertical end-frames 12 at each end thereof.

Each end-frame 12 is shown as having a pair of vertical legs 14 shown of U-shape in cross-section and held in spaced relationship by horizontal rods 16 extending between the legs 14; and each leg 14 is supplied at its upper end with an upright pin 17 for stacking a series of legframes, and at its lower end with a receiver plate 18 having a hole 20 therein to receive the shank-pin of a caster 22 or the pin 17 of an adjacent leg-frame of a stacked arrangement.

The working platform 10 comprises a pair of side-rails 24, and end-rails 26, all shown of downwardly open U- shape in cross-section, and secured together as by welding into a unitary frame; and sheeting 28 such as of planking, tread-plate or plywood is suitably mounted thereon.

According to supportand adjustment-concepts of the present invention, the platform 10 carries adjacent each corner thereof a vertically-extending support 30, shown of U-shape in cross-section, which opens inwardly of the end-frame in embracing relation with its associated end-frame leg 14. The support 30 is shown as braced by a brace 31 extending from the platform 10 to a lower portion of the'support 30.

To each such support 30, there is shown secured as by welding a releasable holding means indicated generally by -reference numeral 32. The holding means 32 is shown as comprising a holding pin such as a plunger 34 slidably carried for axial movement by a nipple or sleeve 36 shown as screwed into a frame plate 38. The plate 38 carries a frame member 40, shown of C-shape which provides the function of guarding the pin and bottoming the spring 44; and the assembly of frame plate 38 and member 40 is shown welded to the support 30.

According to concepts of the present invention, the nipple is externally threaded with male threads 38a; and to the pin 34 there is axially fixed as by welding 41, a threaded collar member 42 having female threads 43 concentric to the axis of the pin 34 and being of a size to screw onto the nipple-threads 38a, and also having a flange or arms 43a radially extending outwardly, making the overall diameter of the collar member 42 and the flange or arms 43a substantially larger than that of the nipple 36, facilitating manual manipulation of the collar member 42 as hereinafter described.

Between the central portion of frame member 40 and the collar 42 there is disposed a compression spring 44, the spring 44 surrounding the pin 34; and the ends of the spring 44 bottom, respectively, on member 40 and collar 42. The spring 44 serves a double function, both of urging the pin 34 to a (rightward) latching position as detailed below, and of maintaining a tight frictional engagement of the screwthreads 38a-43. With that threaded engagement being maintained by the spring 44, the threads 3811-43 need not be tight; and thus the engagement and disengagement of that threaded connection, discussed below, by rotational manual manipulation of the flange or arms 43a by the operator, is relatively easy and convenient.

Co-operating with the pin 34, the end-frame legs 14 are provided with a vertical series of supporting abutments shown as holes 46, each adapted to supportingly receive a holding pin 34.

The latching effect will now be described.

FIG. 3 illustrates the latching parts in a partially-retracted position, the threaded members 3841-43 being disengaged. To effect a full release of the latch-pin 34', the user would push leftwardly on the collar-arms 43a, permitting the pin 34 to move (leftwardly) out of the hole 46. The rear (left) end of the member 40 is provided with an opening 48 in line With the axis of the nipple 36 and pin 34, accommodating axial movement of the pin 34; and the opening or hole 48 is desirably of small enough size as to provide a support for the pin 34. The pin 34 is also shown supported by the support 30 and by the nipple 36 (part of which is shown broken away in FIG. 3).

After release of the latch associated with each of the two legs 14 at one end of the scaffold, the user raises or lowers the platform to its desired height, while holding the pins 34 withdrawn from any of the holes 46, against the bias of the spring 44 of each, by holding the collar flanges or arms 43a.

When the height is approximately correct, he releases those flanges or arms 43a; and when the support comes to the location at which the pin 34 is in register with one of the leg-holes 46, the bias of spring 44 pushes the pin to an intermediate latched position indicated by the fragmental chain line 3401 which indicates the plane in which the front (right) end of the pin 34 is disposed, the position also being indicated by the fragmental chain line 42a which indicates the position of the collar 42 abutting the rear (left) end of the support nipple 36. In this intermediate position (34a and 42a), the pin 34 .is latched into, and extends through, the leg-hole 46, holding the desired height-adjustment.

Further safety is achieved by then revolving the collar 42 a few turns, engaging a few turns of the threads 38a and 43, which moves the pin 34 into an even moresecurely latched position (indicated by fragmental chain lines 3422 and 42b of the pin 34 and collar 42 respectively) and assures that no inadvertent axial force-application, to move the pin 34 axially, can then move the pin 34; for the threads 38a and 43 must be dis-engaged to permit unlatching axial withdrawal of the pin 34.

Unlatching is provided by the collar arms or flange 43a, these serving to be a single component to which both revolving force may be applied to effect rotational disengagement of the threads 38:: and 43, and to which a subsequent axial force :may be applied to withdraw the pin 34 from its latched position in the leg-hole 46.

The height-adjustment is thus quite convenient, requiring no tools and but little time and effort; but the support is quite sturdy and is automatic upon release of the height-adjustment means, achieving maximum safety with no possibility of slippage or illusory partial-securement of the parts.

Also, extra safety is obtained, for the support pins 34 are not only spring-pressed into latching position, but that latched position is made doubly secure and safe by the screw-threaded safety lock at 38a and 43. Moreover, double function is obtained by a single spring 44, it serving both to bias the pin 34 into latched position, and also to maintain a tight threaded engagement of the safety threads 38a and 43. Double function and convenience are obtained also by the collar flange or arms 43a which serve both as a force-application member both for the torque force for the unscrewing of threads 38a and 43, and for the axial withdrawal of the pin 34.

Accordingly, it will be seen that the present invention provides a novel adjustable scaffolding, providing economy of construction, sturdiness, convenience and quickness of height-adjustment with no tools, and maximum safety.

It will thus be seen from the foregoing description of the invention according to the illustrated embodiment, considered with the accompanying drawings, that the invention provides a novel and advantageous adjustable scaffolding having desirable characteristics, and accomplishing its intended objects, including those hereinbefore pointed out and others which are inherent in the invention.

It will be understood that modifications and variations may be effected without departing from the scope of novel concepts of the invention; accordingly, the invention is not to be considered limited to the specific form or arrangement herein described and shown.

What is claimed is:

1. Adjustable scaffolding, of a type which includes:

a platform;

a vertically extending leg;

means supporting said platform for guided movement with respect to said leg;

releasable latch means operatively co-operating between the platform and the leg to releasably secure a selected position of the Platform with respect to the leg;

the latch means including holdingly co-operating means operatively carried by each of said platform and said means for releasing said co-operating means from holding relationship;

and spring-pressure means biasing said latch means into holding relationship;

the improvement, to said type of scaffolding, comprising the latch means including an axially-movable pin means, and support means operatively connected to said platform and supportingly guiding the said pin means for axial movement, there being provided releasable co-operative first and second holding means associated respectively with the platform and the pin means for retaining the said pin means in latched position when the said first and second holding means are operatively engaged with one another, said first and second holding means being of a type which are releasable by a force applied laterally of the axis of the said pin means.

2. The invention as set forth in claim 1, in a combination in which the said first and second holding means are screw-thread means.

3. The invention as set forth in claim 1, in a combination in which the said holding means are operatively concentric with the axis of the said pin means.

4. The invention as set forth in claim 1, in a combination in which the pin means is rotatable with respect to the said support means, and the said second holding means is operatively axially fixed to the said pin means.

5. The invention as set forth in claim 1, in a combination in which the said first holding means is carried by said support means.

6. The invention as set forth in claim 1, in a combination in which the said pin means is in engaged position with respect to the said holdingly co-operative means carried by the scaffold leg when the said first and second holding means are in operatively holdingly engaged position and also when they are in abutment although not in holdinglyengaged position.

7. The invention as set forth in claim 1, in a combination in which the spring-pressure means is effectively bearing upon said second holding means and thus serves also to maintain a tight engagement of the said first and second holding means.

8. The invention as set forth in claim 1, in a combination in which the said second holding means is carried by a force-application member which serves both to accept the said lateral force application to disengage said first and second holding means and also a force application to move the pin means to disengaged position with respect to the said holdingly co-operative means carried by the scaffold leg.

9. The invention as set forth in claim 7, in a combination in which the said first and second holding means are screw-threaded means.

10. The invention as set forth in claim 8, in a combination in which the said first and second holding means are screw-thread means.

11. The invention as set forth in claim 9, in a combination in which the said second holding means is carried by a force-application member which serves both to accept the said lateral force application to disengage said first and second holding means and also a force application to move the pin means to disengaged position with respect to the said holdingly co-operative means carried by the scalfold leg.

References Cited UNITED STATES PATENTS REINALDO P. MACHADO, Primary Examiner. 

1. ADJUSTABLE SCAFFOLDING, OF A TYPE WHICH INCLUDES: A PLATFORM; A VERTICALLY EXTENDING LEG; MEANS SUPPORTING SAID PLATFORM FOR GUIDED MOVEMENT WITH RESPECT TO SAID LEG; RELEASABLE LATCH MEANS OPERATIVELY CO-OPERATING BETWEEN THE PLATFORM AND THE LEG TO RELEASABLY SECURE A SELECTED POSITION OF THE PLATFORM WITH RESPECT TO THE LEG; THE LATCH MEANS INCLUDING HOLDING CO-OPERATING MEANS OPERATIVELY CARRIED BY EACH OF SAID PLATFORM AND SAID LEG; MEANS FOR RELEASING SAID CO-OPERATING MEANS FROM HOLDING RELATIONSHIP; AND SPRING-PRESSURE MEANS BIASING SAID LATCH MEANS INTO HOLDING RELATIONSHIP; 